In accordance with a LTE radio access network (RAN) and with reference to FIG. 1, Third Generation Partnership Project (3GPP) has standardized a SRVCC to provide seamless service continuity when a UE 102 performs a handover from an Evolved Universal Terrestrial Radio Access (E-UTRAN) to UTRAN/GSM EDGE Radio Access Network (GERAN). In the SRVCC, calls are anchored in an IMS network while the UE is capable of transmitting/receiving information, signal, or data on only one of those access networks at a given time. Thus, the call anchored in the IMS core can be continued in a UMTS/Global System for Mobile Communications (GSM) networks and/or outside of the LTE coverage area.
Due to a Circuit Switched Fall Back (CSFB) limitation of drop in data rates when the UE falls back to a 2G/3G network during a voice call, SRVCC handover is desired. The SRVCC is desired where LTE is distributed over some area, an operator wants to use IMS based Voice over LTE (VoLTE) calls in LTE, and this call is handed over to the existing 2G/3G network as a normal Circuit Switched (CS) call when device is moving out of the LTE coverage, as illustrated in FIG. 1.
In such scenarios, some problems through IMS Call establishment in progress and Early Media may occur. For example, if the UE 102 moves to the 3G network coverage, a call drop may be encountered. This call drop could be due to inactivity of data and/or Radio Resource Control (RRC) connection release. When the RRC connection is released, a Measurement Report (MR) may not be sent and SRVCC may not be performed.
Thus, methods and/or equipment by which the synchronization between the UE 102 and the network entity can be effectively maintained while mitigating or preventing any call drop event occurrences are being desired.